KR102127274B1 - Low pressure UV emitter with multiple filaments - Google Patents

Abstract

The present invention relates to a low pressure mercury gas discharge infrared lamp, comprising a tubular elongated body (2) having two opposite ends, a first end (4) and a second end (5), wherein the gas filling (gas filling) 3 is accommodated, the main body has at least two electrical connections at each end, the electrical connections are electrically connected to at least one filament provided at each end, and a discharge length ( l) is the length between the filaments, at least two filaments (a, c and b, d) are provided at each end of the discharge length (l), and the filaments (a, c; b, d) Silver can be supplied with electrical energy individually, and at least two filaments (a, c) at the first end 4 have different sizes and different masses, and at least 2 at the second end 5 The dog filaments (b, d) are characterized by having different sizes and different masses.

Description

Low pressure UV emitter with multiple filaments

The present invention relates to a low pressure mercury gas discharge lamp of the type used for disinfection purposes using ultraviolet rays and a method of operating such lamps.

Low pressure mercury gas discharge lamps are widely used in the field of lighting, but are also widely used in the field of disinfection because of their excellent sterilizing effect of ultraviolet radiation. In disinfection applications, the terms "UV lamp" and "UV radiator" are used as equivalents of high power low pressure mercury gas discharge lamps. These terms will also be used herein.

The main requirements in lighting applications are balanced spectrum in the visible wavelength range, high light output efficiency and long service life in terms of power consumption, and the requirements of ultraviolet (UV) emitters are different. Since the intensity of UV radiation is directly related to the disinfection efficiency, the UV output should be very high, which means that fewer UV emitters with higher UV output can be used to disinfect water and are needed for disinfection plants for drinking water or waste water. This means that investment can be reduced directly. Another important requirement for disinfecting UV emitters in large installations is total power consumption. The amount of water per unit of time in drinking water and waste water treatment (ie, cubic meters per second) can vary widely. In order not to waste unnecessary amounts of ultraviolet light and electrical energy associated with its generation, several techniques have been developed to match the amount of UV plants generated to the water flow. There are solutions where water is treated in multiple parallel channels, each channel is equipped with multiple UV emitters, and individual channels can be closed when the water flow is low. Other uses offer the possibility of reducing the power input of the lamps, thus dimming the lamps to a lower UV output when the water flow is low. Dimming UV lamps of low-pressure mercury type are limited to about 30% of the rated power output because the filaments at the ends of the lamp are heated by the electric discharge of the lamp, and when the power supplied to the discharge is reduced , The temperatures of the filaments are also reduced. At some point, the filaments are too cold to provide the necessary electron emission. There is a risk that the lamp will stop working, and there is a risk of damaging the filament when operating at too low temperatures. Therefore, there is a lower limit for the electrical input of UV lamps.

For lighting purposes, a number of prior art documents using one or more filaments at each end of the lamp are known. These prior art documents are Chinese patent application CN 1812677 A and Chinese patent CN 101644389 B and US patent US 6,756,745 B1. These lamps are used for lighting purposes, and suggest a plurality of overlapping filaments in the sense that one filament can be turned on in the event of a defect. There is no disclosure that the size and mass of the filaments may be different. As mentioned above, the technical problems of lighting applications are different from UV disinfection applications.

Accordingly, it is an object of the present invention to provide a UV low pressure mercury gas discharge lamp with the ability to safely operate at low power levels, i.e. less than 30% of rated power output and especially less than about 10% of rated power output. Another object of the present invention is to provide a method for operating a UV low pressure mercury gas discharge lamp in which different power levels are varied, at least 4 times and preferably 10 times, especially between the lowest power and the highest power. will be.

This object is achieved by a UV low pressure mercury gas discharge lamp with the features of claim 1 and a method of operating such a lamp with the features of claim 10.

The desired effect is achieved in a lamp having the features of claim 1 by providing two filaments at each end of the discharge length, the filaments can be supplied with electrical energy individually, and the filaments at each end have different sizes and different masses. And the difference is greater than the difference due to inevitable production inaccuracies. This structure allows the lamp to operate in different modes, i.e., a high power mode in which electrical energy is supplied to a filament having a larger mass and a low power mode in which electrical energy is supplied to a filament having a smaller, smaller mass. . In particular, the object of the present invention is a low pressure mercury gas discharge ultraviolet lamp, comprising a tubular elongated body having two opposite ends, a first end and a second end, in which gas filling is provided. Is accommodated, the body has at least two electrical connections at each end, the electrical connections are electrically connected to at least one filament provided at each end, and the discharge length is the length between the filaments , At least two filaments are provided at each end of the discharge length, the filaments can be individually supplied with electrical energy, the at least two filaments at the first end have different sizes and different masses, the The at least two filaments at the second end are solved by a low pressure mercury gas discharge ultraviolet lamp of different size and mass.

Optionally, the two filaments can be powered simultaneously, resulting in higher power input and thus higher UV output. When power is supplied to the smaller and lighter filaments, the required operating temperature of the smaller filaments can be reached at lower power input levels because of the small surface area, and thus the mass to be heated by the energy of the discharge arc is small. Because. At a given power, the temperature of the smaller filaments will thus be higher than the temperature of the larger filaments. Consequently, if there is a lower limit of operating temperature, the lamp can be operated at a low power input level as low as 10% of the rated power input. This lower limit has not been achieved so far. The lamp can be operated at this power for a long time without damaging the filament.

Two preferred embodiments will be described with reference to the drawings:
1 is a low pressure gas discharge lamp with four filaments in contact individually;
2 is a low pressure gas discharge lamp with four filaments, each pair of filaments having one common connection;
3 is an axial view of the filament arrangement; And
4 is an axial view of an alternative filament arrangement.

1 shows a low pressure mercury gas discharge lamp 1 with a cylindrical quartz body 2 in the longitudinal direction. Inside the body 2 there is usually a gas filling 3 containing noble gas and a small amount of mercury. The opposite two ends, the first end 4 and the second end 5, are provided with filaments a, b, c and d. The filaments are two electrical connections, namely the electrical connections (a1, a2) of the filament (a), the connections (b1, b2) of the filament (b), the connections (c1, c2) and the filaments of the filament (c) It is supported inside the lamp body 2 by two electrical connections of the connection parts d1 and d2 of (d), respectively. The connections a1 to d2 are electrical conductors of sufficient temperature resistance to melt into the quartz body 2, and have sufficient stiffness to support the filaments a to d under mechanical load that can be expected under operation. . Further, the filaments can be mounted staggered to the lamp.

As shown in Figure 1, the filaments a and b are filaments of relatively short length. These filaments are covered with known materials to improve electron emission under elevated temperatures.

Similarly, the filaments c and d are relatively long filaments. The filaments c and d have the same mechanical and physical composition as the filaments a and b, but are significantly longer. Preferably, the filaments (a and b) on one side and the filaments (c and d) on the other side are made of the same basic wire material, so that the difference in the length of the filaments leads to different masses of the filaments. The filaments a and b are lighter than the filaments c and d. In addition, the filaments can be made of different materials.

FIG. 2 shows an arrangement similar to FIG. 1. The same reference numerals are used for the same or similar components.

In FIG. 2, one embodiment uses a first pair of smaller filaments (a and b) and a second pair of larger filaments (c and d). However, in this embodiment, the filaments at the end portion 4 of the lamp 1 share a common electrical connection ac. This means that the smaller filament (a) can be contacted through the two electrical connections (a1 and ac), while the second filament (c) can be contacted through the connections (ac and c2).

The corresponding arrangement on the other end 5 of the lamp 1 shows the shorter filament b with the electrical connections b1 and bd and the longer filament d with the electrical connections bd and d2. . Thus, the filaments b and d share one common connection bd. The filament b can be in electrical contact through the connections d1 and bd, while the filament d can be in contact through the connections bd and d2.

3 is a view of the filament arrangement viewed in the axial direction. The lamp body 2 surrounds the short filament (a) and the long filament (c). The connections a1, a2; c1, c2 are not visible in this figure. The arrangement of FIG. 3 can be used in embodiments as shown in FIG. 1, where the filaments a and c are individually contacted through four independent connections.

An embodiment with shared connections is shown in FIG. 4. In this embodiment, the lamp body 2 surrounds the filaments a and c, and the filaments a and c are physically and electrically connected to each other at one end. Since the connections a1 and c2 are oriented perpendicular to the plane of the drawing, this end is contacted and held by a common connection ac not visible in the figure.

In operation, the low pressure mercury gas discharge lamp 1 of FIGS. 1 and 2 is a so-called low pressure/high power type of UV emitters. These lamps can operate at a power input of approximately 200 watts. The exact number is not relevant to the current context.

The process of powering the lamp 1 is known from conventional UV emitters of this type. First, DC current is supplied to the connections c1 and c2 of the filament c and the connections d1 and d2 of the filament d (in the embodiment of FIG. 1). The filaments c and d are heated to heat up until a desired temperature for thermal electron emission is reached, that is, about 1,000 K. For heating purposes, the filaments can also be operated with AC current. At this point, high voltage is applied to the filaments c and d through the connections c1 and c2 and d1 and d2 respectively. High voltage can also be supplied to only one connection of each of the filaments c and d. This high voltage induces gas charge in the gas charge 3 and consequently causes ultraviolet radiation. The current passing through the filaments c and d and the plasma carrying the gas discharge inside the lamp is sufficient to maintain the filaments c and d at the desired temperature level required for long service life of the filaments. If the power supplied to the lamp must now be reduced for any reason, for example, the water supply to be disinfected is reduced and less UV radiation is required, the high voltage supply can be reduced in a known manner, which in turn results in a plasma. Less energy is available within, resulting in less temperature in the filaments c and d. This reduction is technically possible to a reduction of about 40% or 30% of the lamp's rated power input. At this point, the filaments c and d are too cold to emit thermal electrons, and the lamp still operates, but the filaments can wear out prematurely.

At this point smaller filaments a and b can be operated. Depending on the configuration of the lamp, the smaller filaments a and b may already be at an elevated temperature sufficient to support gas evolution, or may be preheated by the application of direct current to the connections a1, a2 and b1, b2. have. As soon as the desired temperature of the filaments a, b is reached, they can be powered by a high voltage as described above, and the high voltage supply to the filaments c, d can be cut off. The lamp can now be operated at reduced power input. Smaller filaments with a smaller mass compared to the filaments c and d are heated by a relatively low current that supports gas discharge. However, the lower mass leads to higher temperatures under these operating conditions. Thus, the filaments a and b will still reach a sufficient operating temperature down to reduced power levels of about 30% to 10% of the lamp's rated power input. Physically, a lower mass is equivalent to a lower total heat capacity, and a smaller surface area results in reduction of energy losses through black body radiation. Therefore, switching from the filaments c, d to the filaments a, b can further reduce the power input of the lamp 1 without reducing the life of the filament.

Thus, switching from the filaments c, d to the filaments a, b further reduces the power input of the lamp 1 without reducing the service life of the filaments.

Likewise, the lamp of FIG. 2 can be operated accordingly. The difference in the embodiment of FIG. 2 is that the common filaments ac and bd can be used as ground connections for DC current, while high voltage is generally supplied to the connections c2 and d2 under high power loads and connections under low power ( a1 and b1).

The filaments a, c or b, d on one side may be switched in a pulsed pattern regardless of whether they overlap. Switching of the filaments can occur at or within the end of the UV lamp.

As described in the non-limiting embodiments, the present invention is preferably for UV disinfection plants for drinking water and wastewater, where the power output of UV emitters can be reduced when the amount of water per unit time to be treated is small. Can be used. It is possible to reduce the power of the UV lamp to low power levels, which has never been achieved. This allows operators of these UV disinfection plants to significantly reduce operating costs.

Alternative embodiments not described so far may include two or more filaments at each end.

Claims (8)

Low pressure mercury gas discharge ultraviolet lamp,
It comprises a tubular elongated body (2) having two opposite ends, a first end (4) and a second end (5), in which a gas filling (3) is received, the main body Has at least two electrical connections at each end, the electrical connections being electrically connected to at least one filament provided at each end, the discharge length (l) being the length between the filaments, low pressure mercury gas In the discharge ultraviolet lamp,
At least two filaments (a, c and b, d) are provided at each end of the discharge length (l), and the filaments (a, c; b, d) can be individually supplied with electrical energy, , At least two filaments (a, c) at the first end 4 have different sizes and different masses, and at least two filaments (b, d) at the second end 5 are different Have a different size and mass,
The filaments (a, b, c, d) are respectively connected to the two connecting portions (a1, a2; b1, b2; c1, c2; d1, d2) individually, low pressure mercury gas discharge ultraviolet rays lamp. According to claim 1,
A low pressure mercury gas discharge ultraviolet lamp, characterized in that the mass ratio of the mass of the filaments (c, d) having a larger mass and the mass of the filament (a, b) having a smaller mass is greater than 1.5. A method of operating the low pressure mercury gas discharge ultraviolet lamp according to claim 1,
The lamp is characterized by operating in different modes, a high power mode in which electrical energy is supplied to a filament having a larger size and mass, and a low power mode in which electrical energy is supplied to a filament having a smaller size and mass. , How it works. The method of claim 3,
In the high power mode, the lamp can deliver power at 100% of the rated power output,
In the low power mode, characterized in that the power is reduced to less than 30% of the rated power output. The method of claim 3,
In the high power mode, the lamp can deliver power at 100% of the rated power output,
In the low power mode, characterized in that the power is reduced to 30% to 10% of the rated power output. The method of claim 3,
In the highest power mode delivering power at 100% of the rated power output, characterized in that power is supplied simultaneously to the smaller mass of the filaments (a, c) and the larger mass of the filaments (b, d), How it works. delete delete

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